This invention relates to reciprocatory air motors particularly suitable for operating hand-held power tools such as reciprocatory sanding machines, saws, polishing or filing machines, and the like.
In a reciprocatory hand tool of the above kind driven by an air motor, the moving parts of the tool may reciprocate at relatively high speed, and consequently the moving parts of such tools may develop considerable kinetic energy which must be absorbed at each reversal of the stroke of the tool. If no means is provided in the tool for absorbing the kinetic energy developed by the moving parts of the tool during a stroke, such energy is translated into an impact force at the end of the stroke. These impact forces, which are repeated at the end of each stroke, may, at best, be irritating to an operator using the tool, but more realistically may be harmful both to the tool and to the operator.
The present invention seeks to provide a reciprocatory air motor which incorporates means whereby the kinetic energy developed by the moving parts of the motor (and the equipment it is used to operate) is usefully absorbed, and impact forces produced upon stroke reversals of the motor are effectively minimized.